If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.Functional index analysis of qb square tube - commonly used are Brinell angle (HB), Rockwell angle (HRC) and Vickers angle (HV) of qb square tube. Angle is a gauge needle to weigh the soft and hard level of metal data. The angle method is rarely used to determine the internal angle in the current life. It uses the metal data surface tested under the fixed load of the indenter with a certain number and shape to determine its angle value according to the level of the object.Arnhem, pull the sample to fracture on the tensile testing machine, and then measure one or more mechanical properties. Usually, only tensile strength, yield strength, elongation after fracture and reduction of area are measured. Tensile test is the basic mechanical property test of metal materials. Almost all metal materials have specified tensile test as long as they have requirements for mechanical properties. Especially for those materials whose shape is not convenient for hardness test, tensile test has become the only means to test mechanical properties.Pull square tube:Santa Coloma de Gramenet,Derusting: This is an important process for galvanized square pipes and components before coating, and it is the key to the quality of galvanized square pipes. Thorough derusting can improve the adhesion of antirust paint and prolong the service life of galvanized square pipe.We all know very well. Therefore, the quality of square tubes will directly affect the development of the construction industry. What if we can make the service life of square tubes longer? Here, we also need to ask the personnel of the square tube manufacturer for instructions and use ingenious methods to prolong the service life of the square tube, so that the square tube can bring us greater help in life.Fake and shoddy square tubes are easy to scratch, because the equipment of fake and shoddy material manufacturers is simple and easy to produce burrs and scratch the surface of square tubes. Deep scratches reduce the strength of square tubes.

Section shape classification of large-diameter qb square tube square tube is classified according to section shape: simple section square tube & mdash& mdash; Square tube, rectangular tube and complex section square tube & mdash& mdash; Flower shaped square pipe, corrugated square pipe special-shaped square pipe, large-diameter qb square pipe surface treatment classification square pipe is divided according to surface treatment: hot-dip galvanized square pipe, electro galvanized square pipe, oil coated square pipe, acid pickling square pipe, large-diameter qb square pipe purpose classification square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration, machine tool equipment,Arnhem100 weight of galvanized square pipe, machinery industry, chemical industry, steel structure, shipbuilding, automobile, steel beam and column, special purpose, large-diameter qb square tube wall thickness classification, large-diameter qb square tube according to wall thickness Classification & mdash& mdash; Super large diameter qb square pipe, large diameter qb square pipe and thin-wall large diameter qb square pipe rectangular pipe are the names of square pipe and QB square pipe, that is, steel pipe with equal side length. It is made of rolled strip steel after process treatment. Generally the strip steel is unpacked, leveled, then rolled into a square pipe from the round pipe, and then cut into the required length. Usually pieces per bag. Qb square pipe, also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe, code f and j respectively. The allowable deviation of wall thickness of qb square pipe shall not exceed plus or minus % of nominal wall thickness when the wall thickness is not greater than mm, plus or minus % of wall thickness when the wall thickness is greater than mm, except for the wall thickness of corner and welding joint area.Among them, qb square tube is divided into process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe are divided by weld & mdash& mdash; Straight seam welded square pipe, drill collar, core pipe, casing, sedimentation pipe, etc.quality, there are more and more fake and shoddy square tubes in the market. How to distinguish the fake and shoddy square tubes? Let me teach you some points to distinguish the fake and shoddy square tubes.Change to square pipe: generally, the strip steel is unpacked, leveled, crimped and welded to form a round pipe, then rolled into a square pipe from the round pipe and then cut into the required length. Stage ( & mdash; )There are many processing technologies for square tubes. I won't introduce the specific processing technology here. We only know about the processing technology of each other's tubes. We may have insufficient understanding of its heating technology. Next, I'll give you a detailed introduction to the heating technology of the lower tubes.

The local heat release in the welding process of square tube can reduce the heat affected zone, avoid the micro of thermal sensitive materials, and maintain the properties of materials.Quality recommendation,Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.It is forbidden to degrease the oil square pipes and pipe fittings in the direct production concentration unit air separation unit, oil refining and chemical engineering according to the design requirements. The purpose of degreasing is to prevent the transported or stored materials from being contaminated by grease or organic matter; Avoid mixing transported or stored materials with grease or organic matter; Oil content to ensure the activity of the catalyst; The content of oil and organic matter to ensure the purity of the product. The installed square pipe shall be disassembled into pipe sections for degreasing. Pipes that cannot be disassembled after installation shall be degreased before installation. Square pipes with obvious oil stains or serious corrosion shall be cleaned by steam purging,Arnhem6 galvanized square pipe,ArnhemGalvanized spiral pipe manufacturer, sand blasting or other methods before degreasing.Classification of square tube steel is iron carbon alloy with carbon content of square tube between .% - %. In order to ensure its toughness and plasticity, the carbon content generally does not exceed %. In addition to iron and carbon, the main elements of steel also include silicon, manganese, sulfur, phosphorus, etc. There are various classifications of steel and square tubes, mainly including the following: square tubes are classified into ordinary steel according to quality (P & le; .%, S & le; .%)Arnhem,Square tubes for petroleum cracking (gb-) are furnace tubes, heat exchangers and pipeline square tubes suitable for petroleum refineries.Fatigue strength, plasticity and hardness discussed above are indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.Precision inner diameter square tubes for hydraulic and pneumatic cylinders (gb-) are cold drawn or cold-rolled precision square tubes with precision inner diameter for hydraulic and pneumatic cylinders.